can't get a recording input

I’m not the most technically inclined and am finding this installation pretty difficult. i can’t get any input, even though i unlocked the privacy settings to allow for Audacity to be an input mic. When i click on ‘Sound’ preferences for the Mac, i see the USB PnP Audio Device pop up and then disappear within a second. Like it’s glitching out. doesn’t make sense. i have no idea what to do.

Which version of Audacity?
Which version of macOS?
What is the recording device that you are trying to use?

I have exactly the same issue. I just received my cassette mate cassette to MP3 converter last week and installed Audacity v 2.4.2 on Mac OS Catalina 10.15.7.

“USB PnP Audio Device” is the telltale sign. Both of you probably have the same device under a different name - a small portable cassette deck with a USB port. Mac users have been complaining for years about exactly the symptoms you see - the device shows up then disappears and Audacity reports being unable to connect to the recording device. Note that the device appears and disappears in the Mac’s Sound Preferences - this is an indication that the problem is with the device, not Audacity.

No-one has found a solution.

– Bill

Typically like this, though the paint job and name may differ.